Rome, October 18 - Anti-establishment 5-Star Movement (M5S) bigwig Luigi Di Maio has defended himself from allegations of high spending in the last three years. Lower House Deputy Speaker Di Maio, seen as the M5S's premiership candidate, said the 100,000 euros he spent was "transparent expenditure". Meanwhile another M5S bigwig, RAI State broadcaster oversight commission chief Roberto Fico, has denied leading a group of "rebels" against Di Maio. On Tuesday the Lazio regional administrative court (TAR) is expected to rule on an appeal from the M5S and the Italian Left (SI) party against the wording of the December 4 Constitutional reform referendum. The two parties say the wording is a "misleading advertisement" for the government's campaign for a Yes to an overhaul of Italy's political machinery.